Technologies which, when a vehicle makes a stop, shut down the engine of the vehicle in order to control unnecessary exhaust gas emissions and fuel consumption caused by idling are known.
In such technologies, when the engine is shut down when the compressor and the blower fan are on in order to air-condition (e.g., cool) the cabin, the compressor, which is driven by the engine, is switched off so that air conditioning refrigerant compression and circulation is no longer performed. When air conditioning refrigerant compression and circulation is no longer performed, odor occurs and fogging of the windshield glass and so forth occurs because of the evaporation of liquid from the surface of the evaporator and the blowing out of damp air from the surface of the evaporator.
Patent citation 1 proposes a technology that suppresses unpleasant odor by monitoring the temperature at which condensate on the evaporator dries during engine shutdown and starting up the engine to thereby cause the compressor to operate before the condensate dries. Specifically, in the process of the evaporator outlet temperature increasing to the high temperature side at the time when the compressor is shut down, the technology determines a temporary drop in the evaporator outlet temperature, which arises just before the condensate on the surface of the evaporator completely dries, and restarts the compressor.